The bridge aerodynamics research community is currently discussing several nonlinear wind load models for bridge decks, but no definite conclusion on which model is superior to the others is currently available. In this paper, we use experimental data for a double-deck section model tested in an advanced forced vibration rig to study the observed nonlinearities and to gain insight into what characteristics the nonlinear load model should be capable of modelling. Single harmonic horizontal, vertical and pitching motion; combined motion; and stochastic motion are considered. This approach allows the investigation of a more extensive range of nonlinear behaviours than regular wind tunnel testing. The typical nonlinear characteristics observed are mean drift, deviation from superposition and harmonic distortion. Further, we introduce a simple response-surface model for force prediction using polynomial combinations of the inputs and its derivatives. The model helps to gain further insight into the nonlinearity of the problem at hand and to select which refined modelling approach can be used in future work.

桥梁空气动力学研究团体目前正在讨论桥梁甲板的几种非线性风荷载模型，但是目前尚无关于哪种模型优于其他模型的明确结论。在本文中，我们使用在先进的强制振动装置中测试的双层截面模型的实验数据来研究观察到的非线性，并深入了解非线性载荷模型应具有的特征。单谐波水平，垂直和俯仰运动；联合运动 考虑随机运动。与常规的风洞测试相比，这种方法允许研究更广泛的非线性行为。观察到的典型非线性特征是平均漂移，偏离叠加和谐波失真。进一步，我们介绍了一种简单的响应面模型，用于使用输入及其导数的多项式组合进行力预测。该模型有助于进一步了解当前问题的非线性，并选择可以在以后的工作中使用的改进的建模方法。